Synthesis, Characterization, and X-Ray Structures of 2-(3,5-Dimethylpyrazol-1-Yl)Phenyl-Based Organoselenium Compounds and Their Glutathione Peroxidase (Gpx) Like Activity

Abstract

The synthesis of a series of 2-(3,5-dimethylpyrazol-1-yl)phenyl-based organoselenium compounds, (dmpzC₆H₄Se)₂ (1), dmpzC₆H₄SeR (dmpz = 3,5-dimethylpyrazol-1-yl; R = (CH₂)_nY; Y = OH, NH₂, and COOH), and dmpzC₆H₄SeX (X = Cl, Br, or I) is described. The compounds are characterized by IR, NMR (¹H, ¹³C{¹H}, ⁷⁷Se{¹H}), and mass spectral (MS) data. The molecular structures of (dmpzC₆H₄Se)₂, dmpzC₆H₄SeCH₂COOH, and dmpzC₆H₄SeCH₂CH₂OH have been established by X-ray crystallography. The two latter compounds are associated in the solid state through intermolecular hydrogen bonding between the OH proton and the pyrazolyl nitrogen atom of the adjacent molecule. Glutathione peroxidase (GPx) like catalytic activity of these compounds has been evaluated by using hydrogen peroxide (H₂O₂) as substrate and dithiothreitol (DTT^red) as thiol cofactor in CD₃OD, and the progress of the reaction was monitored by ¹H NMR spectroscopy. All the compounds exhibited the GPx-like catalytic activity. Among these, the ones containing alkylamino groups showed the best activity.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

GRAPHICAL ABSTRACT

Keywords:

• GPx mimicking
• organoselenium compound
• NMR spectroscopy
• X-ray diffraction

Acknowledgments

We thank Drs. T. Mukherjee, S. K. Sarkar, and D. Das for encouragement of this work. One of the authors (ASH) is grateful to Board of Research in Nuclear Sciences (BRNS), Department of Atomic Energy (DAE) for the award of a Senior Research Fellowship. We are also grateful to BRNS for the research grant under the Prospective Research Fund (PRF) Scheme (Grant no. BRNS/2007/38/5).

We thank Drs. T. Mukherjee, S. K. Sarkar, and D. Das for encouragement of this work. One of the authors (ASH) is grateful to Board of Research in Nuclear Sciences (BRNS), Department of Atomic Energy (DAE) for the award of a Senior Research Fellowship. We are also grateful to BRNS for the research grant under the Prospective Research Fund (PRF) Scheme (Grant no. BRNS/2007/38/5).